Biological Control Agents Research Articles

Monographs on invasive plants in Europe N°8: Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn

ABSTRACT Cortaderia selloana (Schult. & Schult. f.) Asch. & Graebn. (Pampas grass) is a perennial grass native to temperate and subtropical regions of South America. The species was introduced to western Europe for ornamental purposes during the nineteenth century, where it has become naturalized in anthropogenic and natural habitats, especially in sandy, open, and disturbed areas. Female plants of C. selloana produce thousands of seeds that are dispersed over long distances by wind and germinate readily. Its invasive success is also attributed to its ability to adapt and tolerate a wide range of environmental conditions, such as high salinity levels, long droughts, and soil chemical pollution. Cortaderia selloana usually invades human-disturbed habitats where it encounters little competition with other plants and high resource availability. However, the species can invade natural habitats, especially those with high light availability, causing biodiversity loss and changes in ecosystem functioning (e.g. alteration of succession and nutrient dynamics). The species may cause negative socio-economic impacts by reducing productivity of tree plantations, causing respiratory allergies, and decreasing the recreational value of invaded areas. Control costs are high due to the extensive root system that C. selloana develops and the high resprouting ability following physical damage. Although herbicides are effective control measures, their use is not allowed or is undesirable in all situations where the plant occurs (e.g. near riverbanks, natural protected sites). No biological control agents have been released on C. selloana to date, but the planthopper Sacchasydne subandina and the gall midge Spanolepis selloanae are promising targets.

Improved control of Trialeurodes vaporariorum using mixture combinations of entomopathogenic fungi and the chemical insecticide spiromesifen

Greenhouse whitefly (Trialeurodes vaporariorum) is a major global pest, causing direct damage to plants and transmitting viral plant diseases. Management of T. vaporariorum is problematic because of widespread pesticide resistance, and many greenhouse growers rely on biological control agents to regulate T. vaporariorum populations. However, these are often slow and vary in efficacy, leading to subsequent application of chemical insecticides when pest populations exceed threshold levels. Combining chemical and biological pesticides has great potential but can result in different outcomes, from positive to negative interactions. In this study, we evaluated co-applications of the entomopathogenic fungi (EPF) Beauveria bassiana and Cordyceps farinosa and the chemical insecticide spiromesifen in laboratory bioassays. Complex interactions between the EPFs and insecticide were described using an ecotoxicological mixtures model, the MixTox analysis. Depending on the EPF and chemical concentrations applied, mixtures resulted in additivity, synergism, or antagonism in terms of total whitefly mortality. Combinations of B. bassiana and spiromesifen, compared to single treatments, increased the rate of kill by 5 days. Results indicate the potential for combined applications of EPF and spiromesifen as an effective integrated pest management strategy and demonstrate the applicability of the MixTox model to describe complex mixture interactions.

Tapping for love: courtship, mating, and behavioral asymmetry in two aphid parasitoids, Aphidius ervi and Aphidius matricariae (Hymenoptera: Braconidae: Aphidiinae).

Understanding the biology and ecology of parasitoids can have direct implications for their evaluation as biological control agents, as well as for the development and implementation of mass-rearing techniques. Nonetheless, our current knowledge of the possible influence of lateralized displays (i.e., the asymmetric expression of cognitive functions) on their reproductive behavior is scarce. Herein, we characterized the behavioral elements involved in courtship, and quantified the durations of 2 important aphid parasitoids, Aphidius ervi Haliday and Aphidius matricariae Haliday (Hymenoptera: Braconidae: Aphidiinae). We quantified the main indicators of copulation and examined the occurrence of lateralized traits at population level. Results indicated that A. matricariae exhibited longer durations of wing fanning, antennal tapping, pre-copula and copula phases compared to A. ervi. Postcopulatory behavior was observed only in A. matricariae. Unlike other parasitoid species, the duration of wing fanning, chasing, and antennal tapping did not affect the success of the mating of male A. ervi and A. matricariae. Both species exhibited a right-biased female kicking behavior at the population level during the pre-copula. Our study provides insights into the fundamental biology of aphidiine parasitoids and reports the presence of population-level lateralized mating displays, which can serve as useful benchmarks to evaluate the quality of mass-rearing systems.

Microbial agents for the control of ticks Rhipicephalus microplus.

Ticks are ectoparasites responsible for the transmission of various pathogens to vertebrates. They represent one of the major threats to livestock production worldwide due to their impact on the health, production and welfare of livestock destined for human consumption. The development of resistance to the main families of ixodicides used for their control has led to the search for new alternatives, where microbial control is an option. The use of microbial control agents against the tick Rhipicephalus microplus is reviewed in this paper. Bacteria such as Bacillus thuringiensis, Serratia marcescens and Staphylococcus spp. the nematodes Steinernema spp. and Heterorhabditis spp. as well as the fungi Metarhizium anisopliae and Beauveria bassiana are the most studied organisms for use as biological control agents against ticks. Laboratory, stable and field trials with free-living and parasitised ticks have shown that microbial agents can control both susceptible and ixodicide-resistant tick populations. However, multidisciplinary studies using novel tools like genomics, transcriptomics and proteomics should be carried out to understand the virulence factors which microbial agents use to induce pathogenesis and virulence in ticks. In addition, applied research will be carried out with the aim of improving techniques for large-scale application, as well as the improvement of cultivation, storage, formulation and application methods.

Study of Population Dynamics of Syrphid Fly (Order- Diptera, Family- Syrphidae) in ITM University Gwalior, India

An intriguing ecological interaction can exist between aphids and Syrphid flies, particularly in the setting of millet crops. Aphids (Order Hemiptera: Family Aphididae) are a problem variety of crops, including all types of millets. Syrphid flies (Order Diptera: Family Syrphidae) naturally prey on aphids when they are in their larval stage. Syrphid fly larvae are referred to as "aphid lions" or "hoverfly larvae." Aphids are the main source of food for these larvae, and they manage the aphid population in millet crops. Therefore, Syrphids are used as natural enemies and biological control agents and syrphid flies are advantageous insects in agriculture. The present study was conducted in the month of August 2021 to March 2022 (summer and winter season) to find out the population dynamic of syrphid flies in agricultural farms and the campus of ITM University. The target crops like maize, sorghum, pearl millets, okra, mustard crop, cabbage cauliflower, marigold and brinjal were tagged and marked and Syrphid fly larvae and pupa were counted four times in a month. The larvae and pupa were also collected and kept for adult emergence. The maximum number of larvae were collected from the Turari campus and were as a minimum found in CRC 2. The other predator like lady bird beetles were also observed but their population was very minor. The population of syrphid flies and larvae depends on the climatic conditions and the availability of foods and their prey.

A molecular approach to unravel trophic interactions between parasitoids and hyperparasitoids associated with pecan aphids.

Advances in molecular ecology can overcome many challenges in understanding host-parasitoid interactions. Genetic characterization of the key-players in systems helps to confirm species and identify trophic linkages essential for ecological service delivery by biological control agents; however, relatively few agroecosystems have been explored using this approach. Pecan production consists of a large tree perennial system containing an assortment of seasonal pests and natural enemies. As a first step to characterizing host-parasitoid associations in pecan food webs, we focus on aphid species and their parasitoids. Based on DNA barcoding of field-collected and reared specimens, we confirmed the presence of 3 species of aphid, one family of primary parasitoids, and 5 species of hyperparasitoids. By applying metabarcoding to field-collected aphid mummies, we were able to identify multiple species within each aphid mummy to unravel a complex food web of 3 aphids, 2 primary parasitoids, and upward of 8 hyperparasitoid species. The results of this study demonstrate that multiple hyperparasitoid species attack a single primary parasitoid of pecan aphids, which may have negative consequences for successful aphid biological control. Although further research is needed on a broader spatial scale, our results suggest multiple species exist in this system and may suggest a complex set of interactions between parasitoids, hyperparasitoids, and the 3 aphid species. This was the first time that many of these species have been characterized and demonstrates the application of novel approaches to analyze the aphid-parasitoid food webs in pecans and other tree crop systems.

First report of the nematode‐trapping fungus Arthrobotrys thaumasia in Türkiye and its biocontrol potential against Meloidogyne incognita

AbstractRoot‐knot nematodes, particularly, Meloidogyne incognita, are among the most destructive endoparasitic nematodes, infecting a diverse range of plant hosts. Nematode‐trapping fungi are known for their potential application as biological control agents against plant parasitic nematodes. In the present study, the nematode‐trapping fungus Arthrobotrys thaumasia was isolated from the rhizosphere soil of tomato plants in the West Mediterranean Region of Türkiye. Two hundred and twenty‐three tomato plant rhizosphere soil samples yielded six nematode‐trapping fungal isolates, giving an occurrence frequency of 2.69%. Using morphology and molecular marker sequences (ITS and β‐tubulin loci), the species of the fungi was confirmed to be A. thaumasia. In vitro, A. thaumasia reduced second‐stage juveniles of M. incognita by 77.5% (isolate I‐Y4‐2) and 72.5% (isolate B‐G5‐1). This is the first report on the isolation and characterization of the nematode‐trapping fungus A. thaumasia from Türkiye. Two isolates of A. thaumasia (I‐Y4‐2 and B‐G5‐1) appear to be promising biological control agents that may be utilized for controlling M. incognita‐caused root‐knot diseases.

Influence of propiconazole and metconazole formulations on Bacillus subtilis vegetative cell growth and disease control of fruit crops.

Biological control agent (BCA) Bacillus subtilis formulated as Theia® is registered for control of fungal and bacterial diseases of fruit crops. Combinations of Theia® and strategic concentrations of two demethylation inhibitor (DMI) fungicides were investigated to explore potential synergisms. Bacteria were cultured in nutrient broth and combined with technical grades and two formulations of propiconazole (EC and WP) and metconazole (EC and WDG) at 0, 10, 50, 100, and 150 µg/ml active ingredient. After co-cultivation, optical density (OD600) and colony forming units (CFU/ml) were evaluated. In contrast to EC formulations, the WP or WDG formulations at 10 or 50 µg/ml of both DMIs did not affect vegetative cell growth. The mixture of Theia® and each formulated DMI at 50 µg/ml active ingredient resulted in a significant reduction of Monilinia fructicola lesion development on apple, Colletotrichum siamense lesion development on cherry, and Botrytis cinerea lesion development on cherry. The combination of Theia® with EC formulations showed weaker disease reduction due to antagonism. Only Theia® + non-EC formulated propiconazole and metconazole significantly reduced brown rot disease incidence of apple compared to the respective solo treatments and anthracnose disease incidence of cherry compared to the untreated control. Our results indicated that at least some DMI fungicides possess bactericidal effects depending on the formulation and concentration. The combination of Theia® with a lower than label rate concentration (50 µg/ml) of the DMI fungicides propiconazole and metconazole showed potential for synergistic effects especially when non-EC formulations were used.

Can genomic signatures guide the selection of host-specific agents for weed biological control?

Biological control of weeds involves deliberate introduction of host-specific natural enemies into invaded range to reduce the negative impacts of invasive species. Assessing the specificity is a crucial step, as introduction of generalist natural enemies into a new territory may pose risks to the recipient communities. A mechanistic understanding of host use can provide valuable insights for the selection of specialist natural enemies, bolster confidence in non-target risk assessment and potentially accelerate the host specificity testing process in biological control. We conducted a comprehensive analysis of studies on the genomics of host specialization with a view to examine if genomic signatures can help predict host specificity in insects. Focusing on phytophagous Lepidoptera, Coleoptera and Diptera, we compared chemosensory receptors and enzymes between "specialist" (insects with narrow host range) and "generalist" (insects with wide host range) insects. The availability of genomic data for biological control agents (natural enemies of weeds) is limited thus our analyses utilized data from pest insects and model organisms for which genomic data are available. Our findings revealed that specialists generally exhibit a lower number of chemosensory receptors and enzymes compared with their generalist counterparts. This pattern was more prominent in Coleoptera and Diptera relative to Lepidoptera. This information can be used to reject agents with large gene repertoires to potentially accelerate the risk assessment process. Similarly, confirming smaller gene repertoires in specialists could further strengthen the risk evaluation. Despite the distinctive signatures between specialists and generalists, challenges such as finite genomic data for biological control agents, ad hoc comparisons, and fewer comparative studies among congeners limit our ability to use genomic signatures to predict host specificity. A few studies have empirically compared phylogenetically closely related species, enhancing the resolution and the predictive power of genomics signatures thus suggesting the need for more targeted studies comparing congeneric specialists and generalists.

Potensi Cendawan Antagonis Trichoderma Viride Isolat Bogor sebagai Agensi Pengendalian Hayati Penyakit Antraknosa Tanaman Cabai Merah

Anthracnose disease caused by Colletottrichum capsici on chili plants that can damage yields by up to 80%. Control with fungicides has not been able to provide maximum results, because the fungus can move due to water splashes, especially in the rainy season. The use of antagonistic fungi against Colletotrichum capsici. has been widely published but is still limited to laboratory and greenhouse scales. This study aims to analyze the potential of Bogor isolate Trichoderma viride antagonist fungus against the fungus C. capsici through in-vitro study in the laboratory, screen houses, and field conditions. The experiment was structured using Complete Randomized Design (CRD) with parameters that measured respectively the antagonistic ability, and the percentage of attack by C. capsici and the severity of anthracnose disease on chili plants were both tested in screen house condition. Bogor Isolate T. viride has potential as a biological control agent for chili plants. This is proven by the ability to suppress the growth of C. capsici by 71% in vitro. The use of the fungus T. viride with a concentration of 7x106 conidia/ml (full strength) can suppress the development of anthracnose by 59 to 87% under screen house conditions. In other words, the pathogenicity of capsici in red chili plants shows a severity level of 13 to 41%.

Temporal resource continuity for egg parasitoids of Dalbulus maidis (Hemiptera: Cicadellidae) during winter on irrigated maize crops and edge grasses.

Little is known about winter-season parasitism of eggs of the corn leafhopper Dalbulus maidis DeLong (Hemiptera: Cicadellidae), an important pest of maize throughout the Americas. Our study, conducted in Mexico, aimed to characterize winter-season parasitism of corn leafhopper eggs on maize crops cultivated with drip irrigation and on wild grasses that grow on the edges of maize crops when maize is not present. Maize leaves baited with D. maidis eggs were used to trap the egg parasitoids in the field. In the first year (2022), parasitism of D. maidis eggs was investigated in maize fields planted contiguously on different dates (asynchronous planting). In the second year (2023), parasitism of D. maidis eggs was evaluated in edge grasses and in adjacent maize crops planted on the same date (synchronous). The highest percentage of parasitism (53%), percentage of emergence, and total abundance of egg parasitoids were found in asynchronous maize fields. Here, Anagrus virlai Triapitsyn (Hymenoptera: Mymaridae), Paracentrobia subflava (Girault) (Hymenoptera: Trichogrammatidae), and Pseudoligosita sp. (Hymenoptera: Trichogrammatidae) wasps were found parasitizing the D. maidis eggs, with P. subflava being the most abundant. In wild edge grasses, only P. subflava was found, showing low levels of parasitism, while in synchronous maize, P. subflava increased its percentage of parasitism (up to 37%), percentage of emergence, and abundance, during winter. These results suggest that P. subflava acts as an efficient biological control agent of D. maidis in irrigation-grown maize crops during the winter season, and that edge grasses are overwinter habitats for P. subflava.

Evaluation of the Efficiency of some Biological Control Agents in Inducing Systemic Resistance of Potato Plants Against Black Scale Disease Caused by the fungus Rhizoctonia solani Kühn

Evaluation of the Efficiency of some Biological Control Agents in Inducing Systemic Resistance of Potato Plants Against Black Scale Disease Caused by the fungus Rhizoctonia solani Kühn

Control of schistosomiasis by the selective competitive and predatory intervention of intermediate hosts: A mathematical modeling approach

Schistosomiasis, a freshwater-borne neglected tropical disease, disproportionately affects impoverished communities mainly in the tropical regions. Transmission involves humans and intermediate host (IH) snails. This manuscript introduces a mathematical model to probe schistosomiasis dynamics and the role of non-host snail competitors and predators as biological control agents for IH snails. The numerical analyses include investigations into steady-state conditions and reproduction numbers associated with uncontrolled scenarios, as well as scenarios involving non-host snail competitors and/or predators. Sensitivity analysis reveals that increasing snail mortality rates is a key to reducing the IH snail population and control of the transmission. Results show that specific snail competitors and/or predators with strong competition/predation abilities reduce IH snails and the subsequent infectious cercaria populations, reduce the transmission, and possibly eradicate the disease, while those with weaker abilities allow disease persistence. Hence our findings advocate for the effectiveness of snail competitors with suitable competitive pressures and/or predators with appropriate predatory abilities as nature-based solutions for combating schistosomiasis, all while preserving IH snail biodiversity. However, if these strategies are implemented at insignificant levels, IH snails can dominate, and disease persistence may pose challenges. Thus, experimental screening of potential (native) snail competitors and/or predators is crucial to assess the likely behavior of biological agents and determine the optimal biological control measures for IH snails.

The Efficacy of Local Streptomyces Diastatochromogenes Isolate as a Biological Control Agent of Potato Tuber Soft Rot Disease Caused by Pectobacterium carotovorum in Iraq

The Efficacy of Local Streptomyces Diastatochromogenes Isolate as a Biological Control Agent of Potato Tuber Soft Rot Disease Caused by Pectobacterium carotovorum in Iraq

Studying on Antifungal Activities of Streptomyces Isolated from Soil and Its Biocontrol Potential Against Fusarium of Chili’s Root Rot Disease

Seven Streptomyces strains from chili farm soil, including Strep-1, Strep-2, Strep-4, Strep-5, Strep-6, Strep-8, and Strep-10, were screened for their antifungal activities against Fusarium sp. of chili's root rot disease. The results showed that Streptomyces sp. Strep-4 and Streptomyces sp. Strep-8 performed potential abilities to control the pathogenic Fusarium of which means of antifungal efficacies were 43,88 ± 3,21% and 51,8 ± 2,54%, in turn. Extensive researches on the effects of inoculum factors on antifungal activity of Streptomyces sp. Strep-8 resulted that this strain spontaneously synthesized the antifungal compounds to control Fusarium in the culture condition with pH 7, 40oC of culture temperature, and 7 days of culture time. The results proved that Streptomyces sp. Strep-8 with its thermophilic ability not only provided significant inhibitory activity against pathogenic Fusarium sp. in vitro also promised to be a potential biological control agent to eliminate this fungus on fields. Moreover, using Streptomyces sp. Strep-8 as a biological control agent helps reduce the use of fungicides which contributes to boosting the sustainability of agricultural ecosystems worldwide.

Interaction of Predatory Ladybird Beetle, Micraspis discolor with Nilaparvata lugens throughout Paddy Growing Seasons

Coccinellidae is a high-interest family that has performed well and is widely distributed. It is valuable in economic service because it acts as an agricultural biological control agent. The Micraspis discolor (Syn=Verania) (Coleoptera: Coccinellidae) is a successful omnivorous predator in rice ecosystem and functions well as a general biological control for maintaining the population of brown planthopper (BPH) (Nilaparvata lugens), the major rice pest worldwide. Studies of natural enemies’ abundance are necessary to increase the practical use of biological control in agriculture. This study investigated the abundance correlation of M. discolor (prey) and rice pest N. lugens (prey) from two different geographical areas of rice fields in west and south Peninsular Malaysia. The cyclone lightrap and sweep net method succeeded in collecting 185 individuals of M. discolor and N. lugens. The study indicated that M. discolor, and the N. lugens collected from Selangor were more numerous than Johor in the ripening phase than in the reproductive and vegetative phases. M. discolor can be found in all stages of rice growth. There are positive correlations between M. discolor and N. lugens in both localities throughout the rice growing season. The positive correlation highlighted that the number of pests has increased parallel to the number of predators and vice versa. The use of M. discolor as a predator is essential in agriculture, along with the treatment of a healthy ecosystem landscape of diverse vegetation combinations, which helps to reduce the use of pesticides.

Bacillus siamensis 3BS12-4 Extracellular Compounds as a Potential Biological Control Agent against Aspergillus flavus.

Aspergillus flavus, the primary mold that causes food spoilage, poses significant health and economic problems worldwide. Eliminating A. flavus growth is essential to ensure the safety of agricultural products, and extracellular compounds (ECCs) produced by Bacillus spp. have been demonstrated to inhibit the growth of this pathogen. In this study, we aimed to identify microorganisms efficient at inhibiting A. flavus growth and degrading aflatoxin B1. We isolated microorganisms from soil samples using a culture medium containing coumarin (CM medium) as the sole carbon source. Of the 498 isolates grown on CM medium, only 132 bacterial strains were capable of inhibiting A. flavus growth. Isolate 3BS12-4, identified as Bacillus siamensis, exhibited the highest antifungal activity with an inhibition ratio of 43.10%, and was therefore selected for further studies. The inhibition of A. flavus by isolate 3BS12-4 was predominantly attributed to ECCs, with a minimum inhibitory concentration and minimum fungicidal concentration of 0.512 g/ml. SEM analysis revealed that the ECCs disrupted the mycelium of A. flavus. The hydrolytic enzyme activity of the ECCs was assessed by protease, β-1,3-glucanase, and chitinase activity. Our results demonstrate a remarkable 96.11% aflatoxin B1 degradation mediated by ECCs produced by isolate 3BS12-4. Furthermore, treatment with these compounds resulted in a significant 97.93% inhibition of A. flavus growth on peanut seeds. These findings collectively present B. siamensis 3BS12-4 as a promising tool for developing environmentally friendly products to manage aflatoxin-producing fungi and contribute to the enhancement of agricultural product safety and food security.

Application of a Standardized Impact Monitoring Protocol (SIMP) to assess biological weed control projects in the State of Idaho, USA

In the USA, the lack of systematic post-release assessments of weed biological control projects demonstrating quantitative effects of biological control agents on target weed densities, population biology, and/or vegetation responses remain a concern. While there are numerous quantitative assessments, overall conclusions are limited in scope by the spatial scale covered, duration of study, potentially confounding factors, or weed parameters measured. The United States Department of Agriculture’s Animal Plant Health Inspection Service is the regulatory agency responsible for biological control agent releases. USDA APHIS requires post-release impact monitoring of target weed populations as part of release permits issued for new biological control agents. However, large scale, long-term impact assessments are rarely conducted for a variety of reasons. To address this problem, biocontrol practitioners developed a standardized impact monitoring protocol (SIMP) for the State of Idaho in 2007. The intent was to collect ecological data which are sufficiently robust for quantitative analysis, while minimizing time spent in the field to make data collection appealing to citizen scientists and land managers. SIMP has since been implemented for ten weed biocontrol systems, with more than fifteen years of monitoring data for some systems. SIMP data are collected along permanent transects and include weed density and size parameters, categorical vegetation community and biocontrol agent abundance data. Data are repeated measures, which are well suited for dynamic population modeling and can be coupled with environmental factors (e.g., climate or soil data) to analyze how processes like climate (and climate change) can drive variation in weed biocontrol agent interactions. SIMP data can be combined with detailed weed, nontarget plant and/or biocontrol agent surveys to add analytical data. Finally, SIMP has also been implemented for two weeds for which biological control agents have not yet been introduced to provide weed and community vegetation data prior to releases.

Effect of Bio Control Agents on Controlling Root Rot and Damping-off Disease of Cucumber Seedlings Caused by Rhizoctonia solani

Root rot and seedlings damping-off disease caused by Rhizoctonia solani is the most damaging disease of cucumber. This disease causes reducing yield in cucumber. This study conducted laboratory and greenhouse conditions to find out the efficacy of biological control agents, Trichoderma harzianum, Bacillus subtilis, the chemical compound Bion, and fungicide revanol. The results of pathogenicity test of R. solani on cucumber seeds showed that R. solanihas led to a significant reduction in the percentage of germination and seed rot compared to the control treatment, which amounted to 100%. The results showed the ability of all control agents used in this study to reduce the incidence of the disease. The Bion (benzothiadiazole) treatment showed significant effect and outperformed the other treatments in increasing the activity of the peroxidase enzyme, which was recorded at 14,440 (unit. minute-1.g wet weight-1). It also achieved the highest significant increase in total phenolics 1.52 (mg -1 . gram wet weight -1). Biological control agent T. harzianum has outperformed on other treatments in causing an increase in the activity of the polyphenol oxidase enzyme, it has recorded 1811.7 (unit. minute - 1 .gram of wet weight - 1 leaf).

Effect of Sex, Age and Temperature on the Functional Response of Macrolophus pygmaeus Ramber and Nesidiocoris tenuis Reuter (Heteroptera: Miridae) on Eggs of Tuta absoluta.

The predatory mirids Macrolophus pygmaeus Ramber (Heteroptera: Miridae) and Nesidiocoris tenuis Reuter (Heteroptera: Miridae) are used for the biological control of Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) and other pests in tomato greenhouses. The functional response of 1-day-old (young) and 10-day-old (old) adult females and males of M. pygmaeus and N. tenuis on eggs of T. absoluta was determined on tomato at two temperatures (20 °C and 25 °C) and LD 16:8. Females of M. pygmaeus exhibited higher predation efficiency than males at both tested temperatures. Young M. pygmaeus females had a higher efficiency than old ones, whereas males had a low efficiency irrespective of age. The predation efficiency of N. tenuis was high (but lower than M. pygmaeus) in both young females and males, although old females had a higher efficiency than the respective males. Our results show that the two predatory species have different functional response characteristics to their prey depending mainly on sex and age, which may affect their role as biological control agents.